Integrated circuits (IC) are sensitive to damage due to mechanical shock. When integrated circuits are manufactured, they are contained on a substrate wafer, such as a silicon wafer. A single wafer may contain several dozen integrated circuits.
These wafers are often transported from one location to another, either in the same manufacturing facility or even from one manufacturing facility to another. The wafers that are to be transported are put into a container. Such a container is shown and described in U.S. Pat. No. 5,724,748. The wafers are stacked upon each other in horizontal fashion.
The wafers are brittle and easily damaged. If a container full of wafers is dropped or jarred, the wafers inside may break due to the mechanical shock. Thus, the container should contain some protection from mechanical shock.
In addition to mechanical shock, integrated circuits are sensitive to damage by electrostatic discharges (ESD) and electrical overstress (EOS). The circuits in integrated circuits are so small that they are easily susceptible to damage due to small charges that may accumulate.
In a wafer container, individual wafers are separated from adjacent wafers by leaf separators. Ideally, the leaf separators should protect the integrated circuits from damage due to electrostatic discharge. If a static charge on an integrated circuit is allowed to build up to a high level, then the charge is more likely to find a path to ground. This discharge results in a high instaneous flow of electrical energy, which flow is likely to overwhelm and damage the integrated circuit. In the prior art, the containers are made with walls impregnated with carbon. This allows electrical charges inside of the container to dissipate through the container walls. Unfortunately, the carbon in the walls sheds and can contaminate the integrated circuits inside of the container.
Thus, what is needed is a system to allow electrical charges on integrated circuit wafers inside of a container to dissipate harmlessly, without contaminating the integrated circuits.